A special session of invited papers entitled, "Psychoacoustics and Physiology of Pitch Perception and Frequency Discrimination," is planned for the meeting of the Acoustical Society of America in Cleveland, Ohio, 12-16 May 1986. There will be six speakers who are specialists in this area, three from the United States and three from Europe. There are two purposes to the special session: (1) to establish a set of alternative directions for future research in pitch perception; (2) to inform psychologists and physiologists, who study the auditory system but who are not specialists in pitch perception, about the current state of pitch perception research so that they may recognize pitch-relevant features in their own experimental data and interpretations. The special session will deal with both the psychoacoustics and the physiology connected with the pitch of sine tones (tonotopically local) of noise and clicks (tonotopically broad) and of complex tones (the elements of speech vowel sounds and music). The work to be presented involves fundamental questions of place and time coding in the peripheral auditory system, questions which are of considerable significance for the encoding of signals in hearing prostheses.